Your test matrix, without a device lab.

API=https://api.clousd.com/v1
AUTH="Authorization: Bearer $CLOUSD_KEY"

# reset qa01 to its clean snapshot and wait for the job
JOB=$(curl -s -X POST -H "$AUTH" \
  $API/devices/qa01/snapshots/v20/restore | jq -r .job.id)
until [ "$(curl -s -H "$AUTH" $API/jobs/$JOB | jq -r .job.state)" \
  != running ]; do sleep 3; done

# install this build and open it
curl -s -H "$AUTH" -F apk=@app-release.apk $API/devices/qa01/apk
curl -s -H "$AUTH" -H "Content-Type: application/json" \
  -d '{"op":"open_app","package":"com.example.app"}' \
  $API/devices/qa01/action

# keep the evidence
curl -s -H "$AUTH" $API/devices/qa01/screenshot -o after.png
curl -s -H "$AUTH" $API/devices/qa01/logs > logcat.txt

# the same steps on four phones at once, 0–5 s apart
curl -X POST https://api.clousd.com/v1/groups -H "$AUTH" \
     -H "Content-Type: application/json" -d '{
  "phones":  ["qa01", "qa02", "qa03", "qa04"],
  "steps": [
    {"op": "open_app",   "package": "com.example.app"},
    {"op": "wait",       "seconds": 3},
    {"op": "if_text",    "text": "Sign in", "skip": 1},
    {"op": "screenshot"}
  ],
  "stagger": [0, 5]
}'
# 202 → progress per phone in job.output

# a key created with a webhook URL receives signed events
POST https://ci.example.com/clousd
X-Clousd-Signature: 9f2c…e41a

{"event": "job.finished", "ts": …, "phone": "qa01", "job": {…}}

# events: job.finished · health.problem · health.resolved
# signature: HMAC-SHA256 of the body · 3 delivery attempts